A map made by the Japanese government that recognizes South Korea's ownership of its easternmost islets of Dokdo was unveiled on Sunday, in a clear piece of evidence refuting Japan's repeated claim to the territory.

The map indicates that Japan's continued territorial claim to the Dokdo islets is wrongfully made as the Japanese government used the map to mark its own territory when it clinched a peace treaty with Allied forces in September 1951 following its defeat in World War II.

The Dokdo islets, which lie closer to South Korea than Japan in waters between the two countries, have been a thorny issue in the countries' relations. South Korea keeps a small police detachment on the islets.

Chung Tae-man, a researcher on Dokdo, recently unveiled a scanned file of the map, drawn by the Japanese government in August 1951, which clearly excludes Dokdo from Tokyo's territory, according to the Northeast Asian History Foundation.

Conservative groups in Japan have insisted that the Dokdo islets were included as its territory on the map, but Japanese researchers have not yet revealed the document.

"Japan has claimed that its peace treaty with allied forces did not state that Dokdo is South Korean territory," Chung said. "But the map shows that Japan and allied forces had recognized South Korea's ownership of Dokdo at that time."

Chung said that he found the scan of the map on a website operated by a conservative Japanese who said the map was obtained from Japan's National Diet Library.

South Korea has denounced Japan's repeated claim to Dokdo, calling it an "unjustifiable" move that will do nothing to help improve already chilly bilateral relations.

South Korea has rejected Japan's claim as nonsense because the country regained its independence from Japanese colonial rule in 1945 and reclaimed sovereignty over its territories, including Dokdo and many other islands around the Korean Peninsula. (Yonhap)